From: Bart Van Assche <bvanassche@acm.org>
To: Weiping Zhang <zwp10758@gmail.com>, hch@infradead.org
Cc: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org
Subject: Re: [PATCH v3] block: add documentation for io_timeout
Date: Thu, 06 Dec 2018 08:06:16 -0800 [thread overview]
Message-ID: <1544112376.185366.230.camel@acm.org> (raw)
In-Reply-To: <CAA70yB7rD_vqMXUvHrQ8SwH-jAyDZeL58TkqABqJ0Y=-p_pjyg@mail.gmail.com>
On Wed, 2018-12-05 at 22:59 +0800, Weiping Zhang wrote:
> Weiping Zhang <zwp10758@gmail.com> 于2018年12月5日周三 下午10:49写道：
> > Christoph Hellwig <hch@infradead.org> 于2018年12月5日周三 下午10:40写道：
> > > Can you please also send a patch to not show this attribute for
> > > drivers without a timeout handler? Thanks!
>
> Is there a simple way do that ?
How about checking the timeout member of struct blk_mq_ops for blk-mq and
checking the rq_timed_out_fn member in struct request_queue for the legacy
block layer?
> Shall we return -ENOTSUPP when user read/write this attribute when
> driver has no timeout handler ?
A much more elegant solution is to introduce a sysfs attribute group for the
io_timeout attribute and to make that group visible only if a timeout handler
has been defined. See e.g. disk_attr_group in block/genhd.c for an example.
Bart.
next prev parent reply other threads:[~2018-12-06 16:06 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-05 14:17 [PATCH v3] block: add documentation for io_timeout Weiping Zhang
2018-12-05 14:40 ` Christoph Hellwig
2018-12-05 14:49 ` Weiping Zhang
2018-12-05 14:59 ` Weiping Zhang
2018-12-06 16:06 ` Bart Van Assche [this message]
2018-12-06 16:19 ` Christoph Hellwig
2018-12-06 16:19 ` Bart Van Assche
2018-12-26 1:51 ` Weiping Zhang
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